I couldn't tell what kind of lights they are.
I'm guessing that, inside the bulb, they are "pretzel-shape" CFL bulbs. ("Compact Florescent Lights"). Those are fairly efficient, but I never found a really, really bright CFL.
6500 lumens sounds like a lot for incandescent: those are the very worst.
Are you considering the very intense "metal halide" bulbs that come in 400, 600 or 1000 watt sizes? Those used to be the "pro choice" years ago, but LED lights are said to be more efficient now, if you can afford the initial purchase price.
I forget how the efficiency of metal halide bulbs compare to T5-HO bulbs, but the metal halides create a smaller but brighter spot, while linear tubes create a wider, more uniform illuminated area. I guess you can spread out intense light with reflective "spreaders" if you use metal halides (MH bulbs).
CFL-pretzels aren't too bad, but T5 or T5-HO linear bulbs might be more efficient (lumens per watt). For example, 4-foot, 4-tube T5-HO fixtures.
